1 files changed, 231 insertions, 0 deletions
diff --git a/src/bt_packet_logger.c b/src/bt_packet_logger.c
new file mode 100644
index 0000000..937747c
--- /dev/null
+++ b/src/bt_packet_logger.c
@@ -0,0 +1,231 @@
+/*
+ * bt_packet_logger.c
+ * com.apple.bluetooth.BTPacketLogger service implementation.
+ *
+ * Copyright (c) 2021 Geoffrey Kruse, All Rights Reserved.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+#include <string.h>
+#include <stdlib.h>
+
+#include "bt_packet_logger.h"
+#include "lockdown.h"
+#include "common/debug.h"
+
+struct bt_packet_logger_worker_thread {
+	bt_packet_logger_client_t client;
+	bt_packet_logger_receive_cb_t cbfunc;
+	void *user_data;
+	uint8_t rxbuff[BT_MAX_PACKET_SIZE];
+};
+
+#define SZ_READ_TIMEOUT 100
+#define PAYLOAD_READ_TIMEOUT 500
+
+/**
+ * Convert a service_error_t value to a bt_packet_logger_error_t value.
+ * Used internally to get correct error codes.
+ *
+ * @param err An service_error_t error code
+ *
+ * @return A matching bt_packet_logger_error_t error code,
+ *     BT_PACKET_LOGGER_E_UNKNOWN_ERROR otherwise.
+ */
+static bt_packet_logger_error_t bt_packet_logger_error(service_error_t err)
+{
+	switch (err) {
+		case SERVICE_E_SUCCESS:
+			return BT_PACKET_LOGGER_E_SUCCESS;
+		case SERVICE_E_INVALID_ARG:
+			return BT_PACKET_LOGGER_E_INVALID_ARG;
+		case SERVICE_E_MUX_ERROR:
+			return BT_PACKET_LOGGER_E_MUX_ERROR;
+		case SERVICE_E_SSL_ERROR:
+			return BT_PACKET_LOGGER_E_SSL_ERROR;
+		case SERVICE_E_NOT_ENOUGH_DATA:
+			return BT_PACKET_LOGGER_E_NOT_ENOUGH_DATA;
+		case SERVICE_E_TIMEOUT:
+			return BT_PACKET_LOGGER_E_TIMEOUT;
+		default:
+			break;
+	}
+	return BT_PACKET_LOGGER_E_UNKNOWN_ERROR;
+}
+
+bt_packet_logger_error_t bt_packet_logger_client_new(idevice_t device, lockdownd_service_descriptor_t service, bt_packet_logger_client_t * client)
+{
+	if (!device || !service || service->port == 0 || !client || *client) {
+		debug_info("Incorrect parameter passed to bt_packet_logger_client_new.");
+		return BT_PACKET_LOGGER_E_INVALID_ARG;
+	}
+
+	debug_info("Creating bt_packet_logger_client, port = %d.", service->port);
+
+	service_client_t parent = NULL;
+	bt_packet_logger_error_t ret = bt_packet_logger_error(service_client_new(device, service, &parent));
+	if (ret != BT_PACKET_LOGGER_E_SUCCESS) {
+		debug_info("Creating base service client failed. Error: %i", ret);
+		return ret;
+	}
+
+	bt_packet_logger_client_t client_loc = (bt_packet_logger_client_t) malloc(sizeof(struct bt_packet_logger_client_private));
+	client_loc->parent = parent;
+	client_loc->worker = THREAD_T_NULL;
+
+	*client = client_loc;
+
+	debug_info("bt_packet_logger_client successfully created.");
+	return 0;
+}
+
+bt_packet_logger_error_t bt_packet_logger_client_start_service(idevice_t device, bt_packet_logger_client_t * client, const char* label)
+{
+	bt_packet_logger_error_t err = BT_PACKET_LOGGER_E_UNKNOWN_ERROR;
+	service_client_factory_start_service(device, BT_PACKETLOGGER_SERVICE_NAME, (void**)client, label, SERVICE_CONSTRUCTOR(bt_packet_logger_client_new), &err);
+	return err;
+}
+
+bt_packet_logger_error_t bt_packet_logger_client_free(bt_packet_logger_client_t client)
+{
+	if (!client)
+		return BT_PACKET_LOGGER_E_INVALID_ARG;
+	bt_packet_logger_stop_capture(client);
+	bt_packet_logger_error_t err = bt_packet_logger_error(service_client_free(client->parent));
+	free(client);
+
+	return err;
+}
+
+bt_packet_logger_error_t bt_packet_logger_receive_with_timeout(bt_packet_logger_client_t client, char* data, uint32_t size, uint32_t *received, unsigned int timeout)
+{
+	bt_packet_logger_error_t res = BT_PACKET_LOGGER_E_UNKNOWN_ERROR;
+	int bytes = 0;
+
+	if (!client || !data || (size == 0)) {
+		return BT_PACKET_LOGGER_E_INVALID_ARG;
+	}
+
+	res = bt_packet_logger_error(service_receive_with_timeout(client->parent, data, size, (uint32_t*)&bytes, timeout));
+	if (res != BT_PACKET_LOGGER_E_SUCCESS && res != BT_PACKET_LOGGER_E_TIMEOUT && res != BT_PACKET_LOGGER_E_NOT_ENOUGH_DATA) {
+		debug_info("Could not read data, error %d", res);
+	}
+	if (received) {
+		*received = (uint32_t)bytes;
+	}
+
+	return res;
+}
+
+void *bt_packet_logger_worker(void *arg)
+{
+	bt_packet_logger_error_t ret = BT_PACKET_LOGGER_E_UNKNOWN_ERROR;
+	struct bt_packet_logger_worker_thread *btwt = (struct bt_packet_logger_worker_thread*)arg;
+
+	if (!btwt) {
+		return NULL;
+	}
+
+	debug_info("Running");
+
+	while (btwt->client->parent) {
+		uint32_t bytes = 0;
+		uint16_t len;
+
+		ret = bt_packet_logger_receive_with_timeout(btwt->client, (char*)&len, 2, &bytes, SZ_READ_TIMEOUT);
+
+		if (ret == BT_PACKET_LOGGER_E_TIMEOUT || ret == BT_PACKET_LOGGER_E_NOT_ENOUGH_DATA || ((bytes == 0) && (ret == BT_PACKET_LOGGER_E_SUCCESS))) {
+			continue;
+		} else if (ret < 0) {
+			debug_info("Connection to bt packet logger interrupted");
+			break;
+		}
+
+		// sanity check received length
+		if(bytes > 0 && len > sizeof(bt_packet_logger_header_t)) {
+			debug_info("Reading %u bytes\n", len);
+			ret = bt_packet_logger_receive_with_timeout(btwt->client, (char *)btwt->rxbuff, len, &bytes, PAYLOAD_READ_TIMEOUT);
+
+			if(len != bytes) {
+				debug_info("Failed Read Expected %u, Received %u\n", len, bytes);
+				continue;
+			}
+
+			if (ret == BT_PACKET_LOGGER_E_TIMEOUT || ret == BT_PACKET_LOGGER_E_NOT_ENOUGH_DATA || ((bytes == 0) && (ret == BT_PACKET_LOGGER_E_SUCCESS))) {
+				continue;
+			} else if (ret < 0) {
+				debug_info("Connection to bt packet logger interrupted");
+				break;
+			}
+
+			btwt->cbfunc(btwt->rxbuff, len, btwt->user_data);
+		}
+	}
+
+	// null check performed above
+	free(btwt);
+
+	debug_info("Exiting");
+
+	return NULL;
+}
+
+bt_packet_logger_error_t bt_packet_logger_start_capture(bt_packet_logger_client_t client, bt_packet_logger_receive_cb_t callback, void* user_data)
+{
+	if (!client || !callback)
+		return BT_PACKET_LOGGER_E_INVALID_ARG;
+
+	bt_packet_logger_error_t res = BT_PACKET_LOGGER_E_UNKNOWN_ERROR;
+
+	if (client->worker) {
+		debug_info("Another syslog capture thread appears to be running already.");
+		return res;
+	}
+
+	/* start worker thread */
+	struct bt_packet_logger_worker_thread *btwt = (struct bt_packet_logger_worker_thread*)malloc(sizeof(struct bt_packet_logger_worker_thread));
+	if (btwt) {
+		btwt->client = client;
+		btwt->cbfunc = callback;
+		btwt->user_data = user_data;
+
+		if (thread_new(&client->worker, bt_packet_logger_worker, btwt) == 0) {
+			res = BT_PACKET_LOGGER_E_SUCCESS;
+		}
+	}
+
+	return res;
+}
+
+
+bt_packet_logger_error_t bt_packet_logger_stop_capture(bt_packet_logger_client_t client)
+{
+	if (client->worker) {
+		/* notify thread to finish */
+		service_client_t parent = client->parent;
+		client->parent = NULL;
+		/* join thread to make it exit */
+		thread_join(client->worker);
+		thread_free(client->worker);
+		client->worker = THREAD_T_NULL;
+		client->parent = parent;
+	}
+
+	return BT_PACKET_LOGGER_E_SUCCESS;
+}